The present invention generally relates to a conveyor chain formed from a plurality of block links. In the conveyor chain of this type, adjacent block links are coupled to each other for relative oscillation in all directions about a conveying direction as well as for reciprocal relative rotation about the conveying direction. More particularly, the present invention is directed to an easier-to-handle conveyor-chain coupling structure in which the adjacent block links can be oscillated smoothly in relation to each other and also reciprocally rotated smoothly in relation to each other with less rattling at the coupled parts thereof.
The conveyor-chain coupling structure of the above type is known from, for example, the Japanese Published Unexamined Application No. 513426 of 1998 in which there is disclosed a product support combined with each of multiple similar conveyance units serially coupled to each other in the form of an endless chain to simultaneously convey products while rotating the latter.
The above product support includes a mount plate with means for coupling the mount plate to two adjacent mount plates before and after the mount plate in consideration, a body fixed to the mount plate, and a rod supported in the body to be axially movable and freely rotatable and having a grip end formed to be removably fixed to an open end of the product.
The coupling means includes a coupling stem provided at one end of the mount plate to support a spherical cap-shaped coupling head to be born by the mount plate adjacent to the one end, and a seat provided at the other end of the mount plate, formed to have a spherical shape complementing the spherical cape shape of the coupling head and having an axial opening formed therein to allow free pass of the coupling stem of the mount plate adjacent to the other end of the mount plate in consideration. The coupling stem is supported for the spherical cap-shaped coupling head to freely be rotatable. A bearing plate is fixed perpendicularly to a free end of the coupling stem by a fixing means. The bearing plate extends generally parallel to a surface of the coupling head opposite to the spherical cap-shaped surface. Further, a toroidal rotating shaft is inserted between the opposite surfaces of the coupling head and bearing plate coaxially with the coupling stem.
While a load is being applied to the aforementioned product support in a direction in which the adjacent mount plates will be moved away from each other, the coupled parts rattle less. However, when a load is applied to the product support in a direction in which the adjacent mount plates will be moved toward each other, the coupled parts rattle much, causing a pulsation, noise or the like during travel of the conveyor chain. In addition, since the coupling between the mount plates is complicated, it is very troublesome to assemble and disassemble the coupling parts and thus maintenance of the coupling parts are not easy. Therefore, the assembling, disassembling and maintenance take a long time.
Accordingly, the present invention has an object to overcome the above-mentioned drawbacks of the related art by providing a conveyor chain coupling structure in which block links can oscillate smoothly in relation to each other and reciprocally rotate smoothly in relation to each other, and which is simple in construction, easy to handle and highly durable.
The above object can be attained by providing a coupling structure of a conveyor chain formed from a plurality of block links (A) coupled to each other, in which adjacent block links (A) are coupled to each other for relative oscillation in all directions about a conveying direction as well as for reciprocal relative rotation about the conveying direction, the coupling structure including according to the present invention a connecting rod (2) projecting from one of conveying-directional ends of the block link (A), a coupling bore (5) formed at the other conveying-directional end of the block link (A), a first toroidal bush bearing (25) having a spherically concave inner surface (26) and provided in the coupling bore (5) at the side of the other conveying-directional end of the block link (A), a second toroidal bush bearing (30) having a spherically concave inner surface (31) provided in the coupling bore (5) at the side of the one conveying-directional end of the block link (A), a stopper (35) provided to block the first and second toroidal bush bearings (25, 30) from coming out of the coupling bore (5), and a spherical bush (20) having a spherically convex outer surface (21), provided between the pair of toroidal bush bearings (25, 30) and fixed to the free end of the connecting rod (2), the first toroidal bush bearing (25) being fitted at the spherical concave surface (26) thereof slidably on a portion, at the side of the other conveying-directional end, of the spherically convex surface (21) of the spherical bush (20), and the second toroidal bush bearing (30) being fitted at the spherical concave surface (31) thereof slidably on a portion, at the side of the one conveying-directional end, of the spherically convex surface (21) of the spherical bush (20).
In the above conveyor chain coupling structure according to the present invention, whether a load is applied to the conveyor chain in a direction in which the adjacent block links (A) will be moved away from each other or in a direction in which they will be moved toward each other, the coupled parts will not rattle, which will thus cause no pulsation or noise during travel of the conveyor chain but will assure a smooth relative oscillation or reciprocal relative rotation of the block links (A).
Further, the coupling between the block links (A) is more simplified, robust and durable than ever, and can be assembled and disassembled more easily. Also, the maintenance and the like can be made more easily. Such jobs will be completed in a reduced time. Thus, the present invention provides a conveyor chain coupling structure very easy to handle.
More specifically, in the coupling bore (5), the first toroidal bush bearing (25) provided at the side of the other conveying-directional end of the block link (A) and second toroidal bush bearing (30) provided at the side of the one conveying-directional end of the block link (A) are blocked by the stopper (35) from coming out from the coupling bore (5), and the spherical bush (20) provided between the pair of toroidal bush bearings (23, 30) is fixed to the free end of the connecting rod (2) so that the first toroidal bush bearing (25) is slidable at the spherical concave surface (26) thereof on a portion, at the side of the other conveying-directional end, of the spherically convex surface (21) of the spherical bush (20) while the second toroidal bush bearing (30) is slidable at the spherical concave surface (31) thereof on a portion, at the side of the one conveying-directional end, of the spherically convex surface (21) of the spherical bush (20). Thus, the spherical bush (20) can easily be installed between the pair of toroidal bush bearings (25, 30) and this assembly can easily be installed into the small coupling bore (5). This installation can be made in any narrow place. Thus, the conveyor chain coupling structure itself can be designed more compact, and also since it is suitable for mass production with a reduced cost of manufacture, an inexpensive conveyor chain can be provided.
In the conveyor chain coupling structure according to the present invention, the coupling bore (5) should have a circular inner wall formed about the conveying direction and on which the toroidal bush bearings (25, 30) in pair are slidable at the outer surfaces thereof and they are reciprocally rotatable about the conveying direction inside the coupling bore (5).
In the above coupling structure, the adjacent block links (A) can be rotated more smoothly in relation to each other about the conveying direction.
In the above conveyor chain coupling structure according to the present invention, the coupling bore (5) should have an engagement step (6) formed along one open end thereof at the side of the other conveying-directional end of the block link (A) and also a stopper recess (7) formed along the open end thereof at the one conveying-directional end of the block link (A) and in which the stopper (35), generally C-shaped, is removably fitted, so that the engagement step (6) and stopper (35) work together to prevent the pair of toroidal bush bearings (25, 30) from coming out of the coupling bore (5).
In the above coupling structure, the pair of toroidal bush bearings (25, 30) can stably be provided inside the coupling bore (5) and can positively be blocked from coming out of the coupling bore (5). In addition, the stopper (35) can easily be fitted into or removed from the stopper recess (7), which will greatly contribute to easier replacement of the toroidal bush bearings (25, 30) and spherical bush (20) as well as to easier and time-saving assembling, disassembling, maintenance, etc. of such components.